(1) Field of the Invention
This invention relates to an application management program, application management method, and application management apparatus, for managing other server computers, and more particularly to an application management program, application management method, and application management apparatus which are capable of remotely starting applications installed on server computers.
(2) Description of the Related Art
Servers provide some services by the use of a plurality of server applications operating in cooperation with each other. For example, a service can be provided by using a Web service function, an application service function, and a database service function operating in cooperation with each other.
In the following description, a function name with “server” attached last suggests a function for service provision that is realized by application software running on a computer. In addition, “server computer” suggests a computer that runs application software for service provision.
In the case where a plurality of server applications are associated with each other in a multilevel system, a client issues a processing request to a Web server. The Web server requests an application server to perform a process according to the request. The application server accesses a database server, if necessary, to acquire necessary data.
In such a multilevel system, server applications can be installed on a plurality of server computers according to their roles. For example, a Web server and an application server are installed on different server computers. If server applications run on individual server computers, load balancing on the functions of the server applications can be performed, which realizes a highly flexible system.
However, if applications that cooperate with each other run on different servers, measures for a trouble may have to be taken to a wide range. Therefore, a technique has been considered, which, if a system failure occurs, reboots each domain (server group) including a process causing the failure, so as to limit the impact area of the system failure to an area on a domain basis (for example, refer to Japanese Unexamined Patent Publication No. 2002-342107).
However, in the case where multilevel applications are installed on individual server computers, there are many precautions that should be considered for system operation, in addition to reboot in the case of failures. Therefore, an administrator has a large burden. To be specific, there are following precautions.
The first precaution is that applications have to be started with taking an operation priority (an operation order) of the applications into consideration. For example, in the case where there is a Web application that uses a database server, a server computer where the database application is installed should be booted before a server computer where the Web application is installed is booted.
The second precaution is that a group of server computers operating in parallel in load balancing mode should operate synchronously. In more detail, in a system where the same application run on parallel server computers, the parallel server computers should be booted in synchronization with each other and the application on all the server computers should be completed in synchronization with each other.
The third precaution is that if an application failure occurs, other applications may have to be interrupted in some cases. In more detail, out of a plurality of server computers running applications, operations to some server computers may fail. In this case, the performance of applications associated with the server computers in failure should be considered. For example, if the start of a database server fails, the start of a Web server having a dependency relation with the database server should be restrained.
As described above, in order to operate multilevel applications on a plurality of server computers, there are many precautions including an operation plan, resulting in an excess burden on an administrator who manages the system. To reduce the administrator's burden, these precautions should be fully considered at designing, which increases a system designer's burden. Many cautions at designing cause design mistakes.